In order to compare the characteristics of different varieties of sweet cherry and to formulate corresponding pruning scheme, hierarchical cluster analysis was conducted for the 14 sweet cherry varieties that were mainly planted in Shanxi Province. The results showed that the 14 varieties of sweet cherry could be divided into two types, Hongmanao and Rainier. Fruit setting rate, branching rate, medium fruit shoot proportion, spur proportion and yield per plant were significantly different between these two types of sweet cherry. The key points of pruning management, to improve the yield of Rainier type, were to increase the fruit setting rate and spur proportion, and to control properly the long and medium fruit shoot proportion.
In this study, 14 representative apricot cultivars in the production were selected as the experimental materials, and their fruit cracking characteristics, as well as the correlations between fruit cracking and influencing factors (e.g., pedcarp structure, mineral elements contents, DW/FW ratio and soluble sugar content) were analyzed to provide some reference for systematic study on fruit cracking mecha- nism of apricot. The results showed the cultivars with small orderly-and compactlyarranged epidermal cells were difficult to crack, while the cultivars with big disorderly-and loosely-arranged epidermal cells were easy to crack. There was no significant correlation between pericarp thickness and cracking index. The correlations between cracking and mineral elements contents of apricot fruit were in the order as Ca 〉 Zn 〉 Mn 〉 Fe 〉 K 〉 Mg 〉 Cu. The cracking index of apricot fruit was significantly negatively correlated with Ca content, was weakly correlated with Zn and Mn contents, and was uncorrelated with Fe, K, Mg and Cu contents. Ca deficiency was the main factor affecting the fruit cracking in apricot. Under the same conditions, the higher the water content is, the lower the cracking index is; and the higher the soluble sugar content is, the higher the cracking index is.